Punching device



Dec. 17, 1963 A. K. scHoTT 3,114,280 V PUNCHING DEVICE Filed Deo. 14,1960 A TTORNE YS United States Patent O 3,114,280 PUNCHING DEVICE ArthurK. Schott, Kenmore, N .Y., assignor to Houdaille Industries, Inc.,Buffalo, N.Y., a corporation of Michigan Filed Dec. 14, 1960, Ser. No.75,771 3 Claims. (Cl. 815-140) This invention relates generally topunching devices of the unitized or subpress type, and more specificallyto improved structure therefor by which larger size perforations may bemade than has heretofore been possible with prior punching devices ofthe `same width.

Although the principles of the present invention may be included invarious perforating implements, a particularly useful application ismade in perforating implements or devices having a single C-frame rigidholder adapted to reciprocably support a punch and stripping assembly inits upper arm, and adapted to support a die in its lower arm, and toreceive a workpiece therebetween for perforation. In devices of thistype, the punching and stripping assembly is reciprocably supported inthe upper arm and is received therein, a bore or `guide opening beingprovided therein for such purpose. It will be readily apparent thatcomponents which effect stripping and punching will have to share theopening in the arm, so that the maximum punch size that can beaccommodated will be somewhat -smaller than the opening therein.

The present invention contemplates a novel arrangement of components tosupport the punch and to support the die so that the size of punch anddie which may be accommodated by a holder of a particular width will besomewhat larger than those previously known in the art.

Accordingly, it is an object of the present invention to provide animproved perforating implement of the unitized or subpress type.

Another object of the present invention is to provide a punching deviceof the low or 'short profile type, which device is adapted to receive,support, and guide punching elements of a larger hole-punching size thanhas previously been possible for a given width of holder.

Yet another object of the present invention is to provide a punching andstripping assembly. comprising components so arranged as to accommodaterelatively large size punches.

A still further object of the present invention is to provide means forsupporting a die in a simplified accurate manner.

Many other advantages, features and additional objects of the presentinvention will become manifest to those versed in the art upon makingreference to the detailed description and the accompanying sheet ofdrawings in which a preferred structural embodiment incorporating theprinciples of the present invention is shown by way of illustrativeexample.

n the drawings:

FIGURE 1 is a side elevational vie-w, partly in crosssection, of apunching device provided in accordance with the principles of thepresent invention;

FIGURE 2 is a cross-sectional view taken along line ll-II of FIGURE 1;and

FIGURE 3 is a cross-sectional view corresponding broadly to FIGURE 2 inorientation, and lshowing a prior art structure for purposes ofcomparison.

As shown on the drawings:

The principles of this invention are particularly useful when embodiedin a perforating implement or hole punching device 16 of 4theself-contained or unitized type of punching apparatus, such asillustrated in FIGURE 1. The punching device 16 includes a holder 11 ofthe C-frame type, having an upper arm 11a and a lower arm 3,114,280Patented Dec. 17, 1963 11b, respectively adapted to support a punchingand stripping assembly 12 and a die 13.

The holder 11 is provided with a unitary cylindrical surface 14 in itsupper rigid arm 11a, the cylindrical surface 14 defining a unitary boreor guide opening 15 Within which the punching and stripping assembly 12is slidably and reciprocably guided and supported.

The punching and stripping assembly 12 includes a stripper sleeve orguiding and stripping sleeve 16, a punch 17, and a stripper spring 18.The guiding and stripping sleeve 16 is disposed at the lower end of thebore 1S and is guided directly thereby, the -sleeve 16 being normallydisposed entirely Within the bore 15. At the upper end of the sleeve 16,there is a smaller internal diameter 19 which is substantiallyconcentrically arranged with a larger internal diameter 20. Intermediatesaid larger and smaller internal diameters 19 and 20, there is providedan internal downwardly directed shoulder 21 which is nearer to the upperend of the sleeve 16 than it is to the lower end. The punch 17 includesa head 22, a shank 23, and a punch bit 24. The head 22 is directlyguided at its outer diameter by the upper end of the bore 15, the upperor distal end of the head 22 being adapted to be engaged by a press ram.The head 22 is rigidly secured to the shank 23, a setscrew or lockscrewand groove arrangement 25 being provided in the illustrated embodimentfor this purpose. The head 22 is provided with a downwardly directedshoulder 26 which abuts a confronting shoulder on the shank 23 so thatthe fastening means 25 is not employed to transmit punching forces tothe punch bit 24. The shank 23 extends coaxially into the sleeve 16,comprises a cylindrical configuration, and is integral with the punchbit 24'. However, it will be noted that the shank 23 is of a diameterless than that of the punch bit, and that it extends through the openingdefined by the smaller diameter 19 in the sleeve 16. The punch bit 24 isnormally disposed entirely 'within the sleeve 16, and therefore has ashorter length than the sleeve in a direction parallel to their axes.The punch bit includes an enlargement 27 at its upper end which alwaysis disposed within the sleeve 16 and which is guided directly thereby atsaid larger internal diameter 2d. Between the shank 23 and the punch bit24 there is therefore provided an upwardly directed shoulder 28 whichnormally abuts the downwardly directed shoulder 21. The eniargement 27'is the largest diameter throughout the length of the shank 23 or punchbit 24. The stripping spring 1S is a compression spring which isdisposed entirely within the bore 15, it thus being concealed from viewand hence protected from interfering or being interfered with. It willbe understood that a particular advantage for such spring disposition isthat it assists in maintaining the overall height of the device 1% at aminimum. The spring 18 is thus disposed between the confronting lowerend of 4the punch head 22 and the upper end of the sleeve 16 to urge thehead 22 and sleeve 16 apart. From a radial standpoint, it will bereadily understood that the spring is immediately adjacent to the punchshank 23 throughout the spring length, .and immediately adjacent to thecylindrical surface 14.

It will be readily understood that the punching and stripping assembly12 may be provided with a punch 17 having a punch bit 24, the lower endof which is shaped to provide a cutting edge which is non-circular It isknown in the art that Isuch a punch must be provided with means forpreventing angular movement thereof about its reciprocation axis.Accordingly, and to this end, the instant device is likewise providedwith structure for precluding punch rotation. It will be read-ilyunderstood that such structure may be omitted `where the punch tip isround, as illustrated, and where included as shown,

the punch tip configuration may be altered as may be desired.Accordingly, to provide angular guidance for the punch 17, the sleeve 16is provided with a first keyway 30 which opens radially outward, andwhich terminates at 31 at a point which is spaced from the lower end ofthe sleeve 16. The sleeve 16 is further provided with a second keyway 32which opens radially inward. The keyways 3?, 32 extend in parallelrelation to each other, and are parallel to the axis of the sleeve 16.In combination therewith, there is provided a rst key 33 which issupported by the upper arm 11a, the key 33 extending into the bore andinto the first keyway 3). A second key 34 is carried by the enlargement27 of the punch bit 24 and extends radially therefrom into the secondkeyway 32. These keys and keyways jointly maintain the angular alignmentof the punch 17 with respect to the holder 11. Since the first keywayterminates a spaced distance from the lower end of the sleeve 16, thekey 33 also serves to prevent removal of the punching and strippingasembly 12. This keying structure otherwise does not restrict suchvertical sliding movement as may be required. The key 33 hereinillustrated includes a threaded portion which has a frictional fit withthe upper arm 11a, and a liattened inner end which is received directlyin the keyway 30. Rotation of the key 33 permits the flats thereon toresigter properly with the keyway 39.

At its lower end, the stripper sleeve 16 is provided with a downwardlydirected recess in which a stripper ring 35 is disposed, being heldtherein by a removable snap ring 36. The Iaperture in the ring 35conforms to the peripheral configuration at the cutting edge of thepunch bit 24, which of course can be considerably smaller than theenlargement 27, and which can be as large as the enlargement 27.

A lifter or lifting spring 37 acts between the upper arm 11 and a snapring carried by the punch head 22, the lifter spring 37 acting toresiliently support the punching and stripping assembly 12 in a positionwherein said assembly is retracted from the die 13 on the lower arm 11b.

The stationary lower arm 11b may also be termed as a base since itslower surface is adapted to be supported either directly on a press bedor on other punch mounting means such as a template which receives apair of pilot pins 4t), 4h. The lower arm 11b is provided with anupwardly directed block supporting surface 41 within which there is anaperture 42 which communicates with the front of the device 10 for slugejection. The arm 11b `further includes a first laterally spaced pair ofmeans 43 which respectively extend on opposite sides of the die 13 andwhich forwardly over the block supporting surface 41. The confrontingvertical portions of the means 43 comprise vertically directed meansagainst which the die 13 abuts. The means for supporting the die furtherincludes a die clamping block 44 which has a block base 45 resting onand supported by the block supporting surface 41. The block base 45 hasan aperture 46 aligned with the aperture 42. The block 44 also includesa second laterally spaced pair of means 47 corresponding generally tothe means 43, the means 47 extending rearwardly in confronting relationto each other and to the die abutment means 43. The means 43, 44 jointlydefine a recess conforming substantially to the external configurationof the die 13, the die 13 thus being disposed within such recess. Aparticularly important feature of this invention is that the bottom ofthis recess is defined solely by the apertured block base 45 of theclamping block 44, and thus the lower surface of the die 13 engagessolely with the clamping block 44. In prior art structures, the die hastypically, in this type of device, rested upon a surface defined jointlyby the base and a clamping block. In such structure, tolerances must beaccurately maintained so that the joint supporting surfaces in an actualarticle lie precisely in the same plane.

4 When that plane is delined by structure which comprises solely aportion of the clamping block, the need for such maintenance oftolerance is obviated, and the likelihood of a slightly cocked die dueto non-planar surfaces is eliminated.

To hold the clamping block in the proper clamping relation, there areprovided a pair of screws or screw means 5&1 which extend to the rear ofthe holder and which are threadably received therein. The screw axis isdeclined slightly so that both a downward and a rearward clamping issimultaneously effected. The axis of each of the screws 50 is disposedbetween the aperture 46 and the outside Wall of the clamping block 44,and is disposed beneath the die 13. The screw means 50 thus removablysecure the block 44 to the lower arm 11b, and clamp the die 13 in afixed position in alignment with the punch and stripping assembly 12.

The die 13 is thus disposed between the die abutment means 43 and theclamping means 44 and is supported solely on the die supporting portionor block base 45 for vertical support. The die 13 is apertured toconform to the configuration of the cutting edge of the punch bit 24,the aperture therein being aligned with the apertures 42 and 46 for slugejection.

When this device 1t) is employed, it is -supported between the bed andram of a press, die support being provided by the lower arm 11b, andpunch guidance being provided by the upper arm 11a. When the ram of thepress acts on the upper end of the head 22, force is transmitted to thepunch hit 24. Upon application of such force, the lifter spring 37 firstyields, permitting the punching and stripping assembly 12 to move as aunit until the sleeve 16 engages the workpiece. Thereafter, furtherdepression of the punch by the ram also causes compression of thestripper spring 1S, and causes the punch bit to move through theworkpiece into the die 13. Upon release of the punching or ram force,energy stored in the springs 18, 37 is released, energy from the spring18 first serving to withdraw the punch bit 24 into the sleeve 16,thereby stripping it from the workpiece, and energy from the spring 37serving to raise the punch and stripping assembly 12 as a unit.

Where the die 13 is provided with a shaped configuration, a key 51supported by the lower arm and locked in position by a screw 52, servesto prevent rotation of the die 13 by extending into the recess in whichthe die is disposed and more particularly into a vertical keyway 53 inthe die 13. It will be apparent that the punch and stripping assembly 12may be utilized to align a shaped die 13, the keying for the same beingomitted. However, it is known to be convenient to have independentkeying for the die 13 so that replacement thereof may be more easilyfacilitated.

One of the primary advantages of this invention is not readily apparentfrom an examination of FIGURES 1 and 2, and FIGURE 3 is thereforeprovided to illustrate and emphasize this advantage. FIGURE 3 representsa prior art structure of a punching and stripping assembly 60 disposedin a holder 61 having a bore 62 identical in diameter to the bore 15. Astripping spring 63 has been provided which is identical in diameter tothe stripping spring 1B. A punch 64 has been provided with a headassembly 65 which likewise is slidable directly in the upper end of thebore 62, the punch being guided for reciprocation by a sleeve 66. Thestripping spring 63 also acts between a collar 67 on the lower end ofthe stripping sleeve and the head 65 of the punch. A guide button 63,supported by means obscured in this view, has an internal configurationconforming to the cutting edge of the punch 66, and thereforecorresponds broadly to the ring 35. These figures have been so scaled asto represent an actual holder width of one and three-fourths inches, theFIGURE l and 2 structure thus being able to accommodate punches capableof making a hole up to seven-eighths inch diameter, while the prior artstructure of FlGURE 3 is capable of accommodating punch structure thatwill produce a hole no larger than one-half inch diameter. Thus for apunching device of the same holder width, the novel structure of thisinvention permits the utilization of punch bits which are nearly twiceas wide in diameter as that which can be accommodated by the FIGURE 3structure. It will be noted that in both instances, the strippingsprings have been retained completely within the upper arm so that thisimprovement has been applied to that class of unitized punches whichprovide a relatively low closed height or shut height.

Other commercial holder widths for this type of device have been sold,and where the instant structure is employed, larger punch sizes may beaccommodated without an increase in holder width. The thickness or widthof the device at the punching and stripping assembly 12 is the same asits width at the clamping block 44, and is the maximum width of theentire device. Using the above example, it is thus apparent that twoseveneighths inch diameter holes may be simultaneously made in aworkpiece by two of these devices, and their centers may be as close asthe holder width, namely one and three-fourths inches. Where widerholders are employed to malte two holes similar to the above examplesimultaneously, the holes cannot be located with their centers thatclose together. Accordingly, under such circumstances, the instantinvention enables doing in one operation what previously has requiredtwo separate perforating operations.

Although various minor modifications might be suggested by those versedin the art, it should be understood that l wish to embody within thescope of the patent warranted hereon, all such embodiments as reasonablyand properly come within the scope of my contribution to the art.

l claim as my invention:

1. in a periorating implement comprising a holder having an upperstationary arm and a lower stationary arm, a punching and strippingassembly slidably supported as a unit in a bore in said upper arm, theimprovement of means for supporting a die in alignment with saidpunching and stripping assembly, comprising in combination therewith: anupwardly directed apertured block-supporting surface on said lower arm;a unitary clamping block having an apertured base carried on saidblock-supporting surface and an upwardly directed die supportingportion; said lower arm having first laterally spaced means extendingforwardly above said die supporting portion of said block integrally anddefining vertical die abutment means; said block having second laterallyspaced means extending rearwardly in confronting relation to said firstlaterally spaced means and defining vertical die clamping means; a diedisposed intermediate said die abutment and clamping means and restingsolely on said die supporting portion of said clamping block, said diehaving an aperture aligned with said apertures; and means for removablysecuring said block to said lower arm in die-clamping relation, withsaid die thereby maintained in alignment with said punching andstripping assembly, said securing means extending beneath said dieadjacent to said bloc" aperture.

2. In a perforating implement comprising a holder having an upperstationary arm adapted to slidably support a punching and strippingassembly, and having a lower arm, the improvement of means forsupporting a die on said lower arm in alignment with the punching andstripping assembly, comprising in combination: a unitary clamping blockremovably secured to said lower arm, said clamping block and said lowerarm each defining opposite portions of the periphery of a die-receivingrecess disposed to support the die in alignment with the punching andstripping assembly, the bottom of said recess comprising solely aportion of said clamping block.

3. In a perforating implement comprising a holder having an upperstationary arm adapted to slidably support a punching and strippingassembly, and having a lower arm, the improvement of means forsupporting a die on said lower arm in alignment with the punching andstripping assembly, comprising in combination:

(a) an upwardly directed block-supporting surface delined by said lowerarm and disposed beneath the punching and stripping assembly;

(b) vertical die-abutment means integral with said lower arm andoverhanging said block-supporting surface and vertically spacedtherefrom;

(c) a unitary clamping block supported on said blocksupporting surface,and having an upwardly directed die support surface extending beneathsaid die-abutment means of said lower arm, and comprising the only diesupport surface for the die, said block having integral verticaldie-abutment means extending upwardly from said die support surface inhorizontally spaced confronting relation to said die-abutment means ofsaid arm, and jointly therewith delining a die-receiving recess; and

(d) releasable securing means acting between said block and said lowerarm for electing clamping of the die in said recess by the two verticaldie-abutment means.

References Cited in the file of this patent UNITED STATES PATENTS190,683 Jenkins May 15, 1877 1,076,384 Mighirian Oct. 21, 1913 2,013,976Wales Sept. 10, 1935 2,151,119 Kiwi Mar. 21, 1939 2,317,424 Wales Apr.27, 1943 2,364,401 Stellin Dec. 5, 1944 2,371,565 Whistler Mar. 13, 19452,815,814 Taylor Dec. l0, 1957 2,882,971 Bennett et al. Apr. 2l, 1959FOREIGN PATENTS 411,077 Germany Mar. 10, 1925 1,135,704 France Dec. 17,1956

1. IN A PERFORATING IMPLEMENT COMPRISING A HOLDER HAVING AN UPPER STATIONARY ARM AND A LOWER STATIONARY ARM, A PUNCHING AND STRIPPING ASSEMBLY SLIDABLY SUPPORTED AS A UNIT IN A BORE IN SAID UPPER ARM, THE IMPROVEMENT OF MEANS FOR SUPPORTING A DIE IN ALIGNMENT WITH SAID PUNCHING AND STRIPPING ASSEMBLY, COMPRISING IN COMBINATION THEREWITH: AN UPWARDLY DIRECTED APERTURED BLOCK-SUPPORTING SURFACE ON SAID LOWER ARM; A UNITARY CLAMPING BLOCK HAVING AN APERTURED BASE CARRIED ON SAID BLOCK-SUPPORTING SURFACE AND AN UPWARDLY DIRECTED DIE SUPPORTING PORTION; SAID LOWER ARM HAVING FIRST LATERALLY SPACED MEANS EXTENDING FORWARDLY ABOVE SAID DIE SUPPORTING PORTION OF SAID BLOCK INTEGRALLY AND DEFINING VERTICAL DIE ABUTMENT MEANS; SAID BLOCK HAVING SECOND LATERALLY SPACED MEANS EXTENDING REARWARDLY IN CONFRONTING RELATION TO SAID FIRST LATERALLY SPACED MEANS AND DEFINING VERTICAL DIE CLAMPING MEANS; A DIE DISPOSED INTERMEDIATE SAID DIE ABUTMENT AND CLAMPING MEANS AND RESTING SOLELY ON SAID DIE SUPPORTING PORTION OF SAID CLAMPING BLOCK, SAID DIE HAVING AN APERTURE ALIGNED WITH SAID APERTURES; AND MEANS FOR REMOVABLY SECURING SAID BLOCK TO SAID LOWER ARM IN DIE-CLAMPING RELATION, WITH SAID DIE THEREBY MAINTAINED IN ALIGNMENT WITH SAID PUNCHING AND STRIPPING ASSEMBLY, SAID SECURING MEANS EXTENDING BENEATH SAID DIE ADJACENT TO SAID BLOCK APERTURE. 